This invention relates to an escalator with a high speed inclined section in which steps move faster in an inclined section than in upper and lower horizontal sections.
Nowadays, a large number of escalators of great height are installed in subway stations or the like. In an escalator of this type, the passenger is obliged to stand on a step for a long period of time, which is often rather uncomfortable. In view of this, a high-speed escalator has been developed. However, in such a high-speed escalator, there is a limitation regarding the traveling speed from the viewpoint of allowing the passengers to get off and on safely.
In view of this, there has been proposed an escalator with a high speed inclined section in which the steps move faster in the intermediate inclined section than in the upper and lower horizontal sections, whereby it is possible to shorten the traveling time for the passenger.
FIG. 6 is a schematic side view showing a conventional escalator with a high speed inclined section described, for example, in JP 51-116586 A. In the figure, a plurality of steps 2 coupled in an endless manner are provided in a main frame 1. The steps 2 are driven by a drive unit (step driving means) 3 and moved to circulate.
A circulation path of the steps 2 has a forward path side section, a return path side section, an upper side reversing section L, and a lower side reversing section M. The steps 2 perform a reversing movement from a forward path side to a return path side or from the return path side to the forward path side in the upper side reversing section L and the lower side reversing section M.
The forward path side section of the circulation path of the steps 2 has a forward path upper side horizontal section A to be an upper side platform portion, a forward path side upper curved section B, a forward path side constant inclination section C, a forward path side lower curved section D, and a forward path lower side horizontal section E to be a lower side platform portion. The return path side section of the circulation path of the steps 2 has a return path upper side horizontal section F, a return path side upper curved section G, a return path side constant inclination section H, a return path side lower curved section J, and a return path lower side horizontal section K.
Next, FIG. 7 is a side view showing the vicinity of the forward path side upper curved section B of FIG. 6 in an enlarged state. A speed variation principle of a variable-speed escalator will be described using this figure. In the figure, the step 2 has a footplate 4 for carrying a passenger; a riser 5 formed to be bent at one end in a longitudinal direction of the footplate 4; and a pair of brackets 6 provided integrally with the footplate 4 and the riser 5 at both ends in a width direction thereof. The riser 5 serves as a riser plate which blocks an opening portion between the footplates 4 adjacent to each other.
A driving roller shaft 7a and a trailing roller shaft 9a are provided to the bracket 6 of each step 2. A pair of rotatable driving rollers 7 are attached to the driving roller shaft 7a. The driving rollers 7 are guided by forward path side drive rails 8a supported by the main frame 1 (FIG. 6).
A pair of rotatable trailing rollers 9 are attached to the trailing roller shaft 9a. The trailing rollers 9 are guided by forward path side trail rails 10a supported by the main frame 1. Note that shapes of the forward path side driving rails 8a and the forward path side trail rails 10a are formed such that the footplate 4 of the step 2 always keeps a level in forward path side sections.
The driving roller shafts 7a of the adjacent steps 2a recoupled with each other by a link mechanism (bending link mechanism) 11. Auxiliary rollers 12 are provided in the vicinity of a curving point P of the link mechanism 11. The auxiliary rollers 12 are guided by auxiliary rails 13 supported by the main frame 1. The auxiliary rollers 12 are guided by the auxiliary rails 13, whereby the link mechanism 11 transforms so as to bend and stretch, and an interval between the driving roller shafts 7a, that is, a gap between the adjacent steps 2 is changed. Conversely, a track of the auxiliary rails 13 is designed such that the gap between the adjacent steps 2 changes.
In addition, although FIG. 7 shows the structure in which the gap between the steps 2 is changed in the forward path side upper curved section B, the gap between the steps 2 is arranged to be changed also in the forward path side lower curved section D with the same structure.
That is, in the forward path side sections, the gap between the adjacent steps 2 is continuously changed in accordance with advance of the steps 2 so as to be the smallest in the upper side horizontal section A and the lower side horizontal section E serving as platform portions, to be the largest in the constant inclination section C, and to change from the largest to the smallest or from the smallest to the largest in the upper curved section B and the lower curved section D.
Next, movements will be described. When the steps 2 of the endless manner are driven by starting-up of the drive unit 3, the driving rollers 7 of each step 2 and the trailing rollers 9 are moved to rotate on the drive rails 8a and the trail rails 10a, respectively. Simultaneously with this, the auxiliary rollers 12 are moved to rotate along the auxiliary rails 13, the link mechanism 11 is transformed according to a shape of the auxiliary rails 13, and the gap between the steps 2 is enlarged or reduced.
Due to the transformation of the link mechanism 11, in the forward path upper side horizontal section A and the forward path lower side horizontal section E, the gap between the steps 2 becomes the smallest, and the adjacent footplates 4 come into a state in which they continue in an identical horizontal plane shape. In the forward path side constant inclination section C, the gap between the steps 2 becomes the largest, and the adjacent footplates 4 displace in a step shape.
In one of the forward path side upper curved section B and the forward path side lower curved section D, the gap between the steps 2 changes from the largest to the smallest, and the adjacent footplates 4 displace from the step shape to the identical horizontal plane shape. In the other of the forward path side upper curved section B and the forward path side lower curved section D, conversely, the gap between the steps 2 changes from the smallest to the largest, and the adjacent footplates 4 displace from the identical horizontal plane shape to the step shape.
In this way, since the gap between the steps 2 changes according to the actuation of the link mechanism 11 following the advance of the steps 2, the steps 2 coupled in the endless manner are moved at a variable speed.
Since the plurality of steps 2 are driven to circulate in the endless manner by the drive unit 3 in the above description, a reversing section is required as a transition section between a forward path section and a return path section. In order to make the reverse of the steps 2 possible, it is necessary to keep a posture of the steps 2 in the reversing section, and for this purpose, it is necessary to regulate a moving route in the reversing section of the driving roller 7 and the trailing roller 9.
Thus, in the conventional escalator with a high speed inclined section as described above, a structure of a reversing section as shown in FIG. 8 (the figure shows an upper side reversing section L) is adopted. That is, forward path side reversing section drive rails 8b of an arc shape, which are fixed in a form extending to the reversing section side from the forward path side drive rails 8a, and return path side reversing section drive rails 8c of an arc shape, which are fixed in a form extending to the reversing section side from the return path side drive rails 8d, are used.
In addition, as to the trail rails, a forward path side reversing section trail rails 10b of an arc shape and a return path side reversing section trail rails 10c of an arc shape, which are fixed in a form extending to the reversing section side from the forward path side trail rails 10a and the return path side trail rails 10d, respectively, are used.
In FIG. 8, in the case in which the steps 2 advance, for example, in a Y direction, the driving rollers 7 move to rotate on the rails in the order of the forward path side drive rails 8a, the forward path side reversing section drive rails 8b, the return path side reversing section drive rails 8c, and the return path side drive rails 8d. The trailing rollers 9 move to rotate on the rails in the order of the forward path side trail rails 10a, the forward path side reversing section trail rails 10b, the return path side reversing section trail rails 10c, and the return path side trail rails 10d. Accordingly, the steps 2 become capable of passing the reversing section in a stable posture.
At this point, the movement of the driving rollers 7 in the reversing section is the same as the movement of a vertex of a polygon when the polygon with an axis of the driving rollers 7 as its vertex rotates. FIG. 9 is an explanatory view showing the movement of the driving rollers 7 in the reversing section of FIG. 8. In FIG. 9, the movement of the driving rollers 7 in the upper side reversing section L is schematically shown.
It is assumed that the driving rollers 7 exist in a position of a white circle in the figure in its initial state. It is assumed that the steps 2 are driven by the drive unit, whereby the driving rollers 7 on the forward path side are moved in a Z1 direction in the figure from the position, and the driving rollers 7 on the return path side are moved in a Z2 direction in the figure to be displaced to a position indicated by a black circle.
At this point, when lengths of an outer periphery of the polygon on the reversing section side of a reference line MN (left side in the figure), that is, a length of a broken line and a length of a solid line are compared between the initial state and the state after the displacement, a slight difference occurs between both the lengths. In this way, in the reversing section, the steps 2 move as the outer peripheral length of the polygon formed by connecting the axes of the driving rollers 7 with straight lines changes little by little on a constant basis.
In the conventional escalator with a high speed inclined section constituted as described above, since the forward path side reversing section drive rails 8b and the return path side reversing section drive rails 8c, for guiding the movement of the driving rollers 7 in the reversing section, are fixed to the main frame 1, the change in the outer peripheral length of the polygon formed by connecting the axes of the driving rollers 7 with straight lines cannot be absorbed, and increase in a drive resistance force of the steps 2 due to increase in a pressing force of the driving rollers 7 to the rails 8b and 8c is caused with the result that a smooth reversing movement cannot be obtained.
The present invention has been made in order to solve the problem described above, and it is therefore an object of the present invention to obtain an escalator with a high speed inclined section that can realize a smooth reversing movement of steps by suppressing increase in a drive resistance force.
To this end, according to one aspect of the present invention, there is provided an escalator with a high speed inclined section comprising: a main frame; a plurality of steps provided in the main frame and are coupled in an endless manner to be moved so as to circulate; a driving roller shaft and a trailing roller shaft which are provided to each of the steps; driving rollers provided to each of the steps and are rotatable about the driving roller shaft; trailing rollers provided to each of the steps and are rotatable about the trailing roller shaft; a plurality of link mechanisms which couple the driving roller shafts of the steps adjacent to each other, for changing an interval between the driving roller shafts by being transformed; rotatable auxiliary rollers provided to each of the link mechanisms; drive rails provided to the main frame for guiding a movement of the driving rollers; trail rails provided to the main frame for guiding a movement of the trailing rollers; auxiliary rails provided to the main frame for guiding a movement of the auxiliary rollers to transform the link mechanisms; and an outer peripheral length change absorbing mechanism provided in a reversing section of a circulation path of the steps for absorbing a change in an outer peripheral length of a polygon formed by connecting axes of the driving rollers with straight lines while guiding the movement of the driving rollers in the reversing section.